1. Field of the Invention
This invention generally relates to devices for providing efficient electrical connection with a generally planar conductor covered with an insulating layer such as paint, rust or stain.
2. Description of the Related Art
There can be various types of electrical connections between conductors. A grounding cable is often connected with an enclosure of a switchboard. A linear conductor is connected with another linear conductor by corresponding terminals. A conductor is connected to a terminal base of a distributor or a planar terminal of an electrical appliance. A large capacity transformer utilizes surface contact between two plate bars. Cables are connected to terminals of a battery. There are numerous other possible connections between conductors.
Such electrical contacts or connections are often hindered by insulating hazards covering contact portions such as paint, dust or rust. Mere connection with a conductor surface painted with insulating paint for pleasing appearance or rust inhibition often renders the connection electrically insufficient. Dust or rust may also inhibit sufficient electrical connections.
To provide an electrically sufficient connection with a planar conductor covered with an insulation layer, an appropriate portion or area on a conductor surface needs to be pretreated or scraped with a file or screwdriver for example. It is very time consuming to provide sufficient scraped areas on a large or complicated appliance, especially if there are many portions to be treated.
Some members of a complicatedly designed appliance cannot be easily or properly grounded partly due to their relative inaccessibility. It is often wishfully expected that ungrounded members of an electrical device will provide indirect grounding by the mere fact that they somehow contact grounded members, which is often proved to be a serious error.
A similar problem arises between a cable conduit and electric cables housed therein. A cable conduit is often made of a conductive material such as a metal, which is generally indirectly grounded or expected to be grounded through conductive portions of an electric apparatus to which the cables in the conduit are connected. However, such grounding is not actively constituted, thus often proving to be insufficient.
There exist a number of makeshift ways to provide grounding where such electrical connections are not originally created, such as by utilizing frames or bodies of electric appliances. Of course, originally constructed electrical connections can be made between electrical cables and terminals of electric appliances, between two flat bars where large current is involved, or between batteries and cables. Those originally created contact areas are generally prepared of copper or aluminum, which are prone to rusting, staining or dusting, possibly adversely affecting electrical connection therewith. To provide reliable electrical conduction between elements, it is often required to remove such insulating substances from the contact areas before electrical connections are made.